Whole cottonseed is produced in large quantities from cotton cultivation. After the cotton has been picked from the boll of the cotton plant, it is processed through a cotton gin that combs through the cotton to separate the seeds from the cotton fibers. The whole cottonseed that is separated from the cotton is covered with a coat of residual cotton fibers, known as "linters" or "fuzz," giving the cottonseed a fuzzy appearance. Thus, whole cottonseed is sometimes referred to fuzzy cottonseed, fluffy cottonseed, or linter-bearing cottonseed.
The cotton gin and the textile producing machinery of the late industrial revolution lead to a dramatic increase of cotton production. At first, the cottonseed was considered to be a waste product of producing cotton and of little commercial value except to the extent needed as planting seed for future crops. In the middle of the nineteenth century, it was discovered that cottonseed could be squeezed to yield a useful oil. Later, the residue of the oil making process was used as a feed supplement for grazing animals. Whole cottonseed has become recognized as being a desirable animal feedstuff because of its rich combination of nutritive protein, fibre, and fat contents, and its availability at a reasonable cost.
The livestock feed industry's requirements for cottonseed are different from the requirements of the planting seed industry. For example, relatively speaking, planting seed is characterized by high quality, high cost, and low volume. Cottonseed for use as a feed, in contrast, is characterized by lesser quality, lower cost, and high volume. Therefore, a high cost per unit volume for improving the flow characteristics of planting seed may be acceptable whereas it would not be acceptable for livestock feed.
Whole cottonseed, however, has some undesirable physical characteristics that make the handling of this feed ingredient difficult. For example, the material has a very low bulk density, which means that it has a large volume for a given weight of material, so that handling and shipping of the material is inefficient. Handling whole cottonseed in most processing equipment used in a feed mill is also difficult. The many soft cotton fibers on the seeds tend to become entangled and cause clumping of the seeds, resulting in very poor flowability. This trait is sometimes referred to as "bridging" of the cottonseeds across an opening, which tends to close or bridge the opening and prevent flow of the material. Thus, the handling characteristics of whole cottonseed are similar to those of common cotton balls available from a retail drug store. The poor flowability characteristics of whole cottonseed creates a need for specialized equipment to transport and handle the cottonseed.
In the past, efforts at delinting the cottonseed have included mechanical or chemical delinting, but the additional processing for this purpose has generally negated the commercial viability of whole cottonseed as an inexpensive feedstuff.
U.S. Pat. No. 5,204,102 issued Apr. 20, 1993 and having Richard G. Coles and Ian J. Broadfoot as named inventors, discloses a process and apparatus for treating cottonseed to make an animal feedstuff. The process preferably includes the steps of initially partially delinting the whole cottonseed by singeing the cottonseed in an open flame and removing the charcoal that is produced during such singeing by abrasion such as passing the flame delinted seed through a buffing trommel. The partially delinted cottonseed is then coated with a "binder" and a "filler" combination to cement the cotton fibers to the seed and provide a cementitious base to which the filler is adhered so as to completely encapsulate the seed and provide an integral flowable product. The binder initially has a sticky or tacky consistency but is capable of setting to a solid state when mixed with the filler. The suitable "binders" are gums such as gum arabic, starches, lignasite, and molasses. The suitable "fillers" are inert mineral powders such as calcium carbonate, lime, diatomaceous earth, forms of clay such as bentonite and kaolin, extruded or textured proteins such as those derived from soybeans, and ground cereal grains such as corn, wheat, barely, maize, and sorghum, and mixtures thereof. Optional "additives" to the coating are generally described as vitamins, minerals, trace elements, veterinarian products for the prevention, control or eradication of disease, and growth stimulating factors. U.S. Pat. No. 5,363,754 issued Nov. 15, 1994 and having Richard G. Coles and Ian J. Broadfoot as named inventors is a continuation-in-part of U.S. Pat. No. 5,204,102 that expands its definition of "binders" to include a syrup such as corn syrup.
U.S. Pat. No. 5,750,466 issued May 12, 1998 and having Thomas C. Wedegaertner, Thomas D. Valco, and William F. Lalor as named inventors discloses coating linter-bearing cottonseed with starch and one or more biologically related materials generally described as being selected from the group consisting of vitamins, feed supplements, oils, fats, ores, rodent repellants, insect repellants, medications, antigermination agents, and preservatives for use as an animal feed and as planting stock. The starch coating is intended to allow the cottonseed to be used in conventional feed handling and seed planting equipment. According to U.S. Pat. No. 5,750,466, the process for coating cottonseed consists essentially of the steps of: (a) spraying linter-bearing cottonseed with a coating consisting essentially of a hot, aqueous, gelatinized starch suspension, optionally containing one or more of the listed biologically related materials; (b) drying the starch suspension coated cottonseed to yield starch coated cottonseed; (c) disaggregating the starch coated cottonseed; and (d) cooling and storing the starch-coated cottonseed.
While these patents have advanced the state of the art of coating whole cottonseed, further improvements in handleability and digestibility would be desirable to make full use of whole cottonseed as a nutritive feed ingredient.